Author Topic: No u joint v drive pics  (Read 1097 times)

PeteW

  • Member
  • *
  • Posts: 436
    • View Profile
    • Email
Re: No u joint v drive pics
« Reply #15 on: December 31, 2017, 02:07:37 PM »
I like what Dales thinking and initially I also think that  a hydraulic drive train seems like a cool idea. I looked into it, ran some numbers and got specs on some pumps and motors. Figuring that we have 40 HP to play with proved to get out of hand very fast. Approximates to about a 4 cu in pump running at 2000 RPM to deliver 35 GPM at 3000 PSI. 

Efficiency is perhaps the biggest drawback. Singe you can't use piston pumps which are the most efficient (noisy and short lived) you may want the smoother operating vane pumps. So your efficiency will be about 60% max. So you are going to need a huge hydraulic heat exchanger. I am also not convinced that you will also need gear reduction on the pump and possibly you will need to retain your Walter V drive 2:1 reduction ratio to reduce the tourque spec on the hydraulic motor.

This article sums it up pretty well.   https://www.sbmar.com/articles/some-tips-experiences-on-hydraulically-driven-sailboats/

As the article states , if you boat is already designed to have a conventional mechanical drive train, you would be crazy to consider hydraulic drive as an alternative for a cruising boat drive train that requires continuous duty.

Pete



« Last Edit: December 31, 2017, 02:14:23 PM by PeteW »

SVTheEdge

  • Member
  • *
  • Posts: 21
    • View Profile
    • Email
Re: No u joint v drive pics
« Reply #16 on: December 31, 2017, 02:15:53 PM »
Prolly the best bet would be to just install another drive shaft.  Can I get a specially made telescoping drive shaft at a car drive train shop? I hate to ask the price of one at Walter Co.  I'm thinking thousands......
Pate B.
1979, 365 ,Hull #244, Sloop
S/V "The Edge"
South Port, NC

S/V AMITY

  • Member
  • *
  • Posts: 37
    • View Profile
    • Email
Re: No u joint v drive pics
« Reply #17 on: December 31, 2017, 03:50:22 PM »
  Just throwing this out for giggles but shafts for tractor PTO's are telescoping AND have u-joints at both ends.  Remove one of the u-joints, add a coupler for the transmission connection and there you are.  These PTO shafts are designed to handle heavy torque and are rated for various horsepowers.  eBay has pages & pages of them.